This phrase is being used with increasing regularity, especially amongst the ex-pat acting communities in Italy. Its meaning is ambiguous to say the least, however it is widely used when letting someone know they should call or email you at a later date. With increasing use (google currently has 9 entries for the phrase) this phrase is sure to go far.
n.b. this is NOT a muddled mess of 'drop me a line' and 'give me a buzz'. This is a phrase all by itself and has no relation to either. Anyone suggesting otherwise will likely find themselves with a libel case against their punk asses.
Actress: So you'll let me know when you hear from them?
Accountant(in an attempted cool voice): Yeah, no worries, just drop me a buzz
Actress (without the blink of an eye): ok, thats fine, i'll drop you a buzz
(both parties left this conversation a bit confused as to what they'd agreed to, unaware that they'd participated in something rare and amazing, the invention of a new phrase!)